Synthesis of carbon quantum dots by chemical vapor deposition approach for use in polymer solar cell as the electrode buffer layer

详细信息    查看全文

• 作者：Lingpeng Yan^a ; ^b ; Yongzhen Yang^a ; ^b ; ^{yyztyut@126.com" class="auth_mail" title="E-mail the corresponding author} ; Chang-Qi Ma^c ; ; Xuguang Liu^a ; ^d ; Hua Wang^a ; ^b ; Bingshe Xu^a
• 刊名：Carbon
• 出版年：2016
• 出版时间：November 2016
• 年：2016
• 卷：109
• 期：Complete
• 页码：598-607
• 全文大小：2491 K

文摘

Fluorescent carbon quantum dots (C-CQDs) with graphitic structure were synthesized by chemical vapor deposition (CVD) for the first time. With this approach, the synthesized C-CQDs exhibit excellent crystaline graphitic nature with an average diameter of 3.5 nm and rich of hydrophobic mg border="0" alt="single bond" data-inlimg="/entities/sbnd" src="/sd/grey_pxl.gif" class="glyphImg imgLazyJSB"><noscript>mg border="0" alt="single bond" src="http://cdn.els-cdn.com/sd/entities/sbnd" class="glyphImg">noscript>CH₃ terminal groups. Optical band gap of the C-CQDs was determined to be 3.16 eV, whereas low-lying HOMO/LUMO energy levels of &minus;7.00/-3.84 eV were measured for these C-CQDs by cyclic voltammetry. Polymer solar cells using solution-processed C-CQDs as the electron transporting layer (ETL) were fabricated and tested. Results indicate the C-CQDs based devices exhibit similar or slightly improved device performance as the LiF based devices. Lowered series resistance (R_S) was found for these C-CQDs based devices, suggesting a better interfacial connection between the Al electrode and polymer with this ETL. More importantly, improved thermal stability was confirmed for the CQD-based devices, which was ascribed to the less diffussion possibility of C-CQDs in solid film. The current work confirmed that the CVD synthesized C-CQDs could serve as a solution processed ETL for use in organic solar cells with improved device stability.